As BRCA1 has been shown to be able to bind EZH2 and negatively regulate PRC2 complex activity,22 and as we have previously shown that both BRCA1 and DMNT3 bind to EZH2 but do not exist in the same complexes in breast cancer cells,23 these lead us to propose that BRCA1 can promote the transcription of FOXO3 indirectly through binding to EZH2 subunit of the PRC2 complex, thereby restraining its methyltransferase activity. This evidence concerns the gene BRCA1 and breast cancer.